Stockport builder FT Finley has won a four-year contract to replace windows and doors at 600 homes for Liverpool Housing Trust.
A combination of sheltered accommodation and social housing, the properties are located in a number of areas, including Norris Green, Croxteth and Anfield.
FT Finley expects the contract to be worth a total of £1.4m over the four-year period.
Managing director Fred Finley said: "By replacing the UPVC windows and doors on these properties, we'll be improving the energy efficiency of the buildings, helping the residents to cut their fuel bills.
"We have a breadth of experience in managing planned and reactive work of this nature and are confident that we can complete this project to a high standard, within the designated time frame."
Damian Whittingham, projects team leader at Liverpool Housing Trust, said: "We evaluated the tender submissions based on quality and cost, and FT Finley stood out from all of the other applications on both counts.
"Having previously worked with FT Finley on other projects, I know that the team is very efficient and can complete jobs with minimal disruption to tenants. FT Finley routinely goes above and beyond expectations and the company was a clear choice for this project."